1. Field of the Invention
The present invention is related to linear guides in general and in particular to a multi-purpose linear band-based guide device configurable both as a traditional linear guide device and as a narrow band conveyor device.
2. Description of Related Art
Linear guides are useful in a machine tool as well as in industrial machines. Conventionally, a guide bearing apparatus comprises a guide rail, a slider or carriage serving as a movable elements and a plurality of balls serving as rolling elements. The balls may be arranged in ball bearing arrangements.
The ball bearing arrangements are used to move the slider or carriage along the guide rail. Typically, the balls are disposed in a circulation passage which composed of a first set of raceway grooves formed in the rail structure and a second set of raceway grooves form a circulation passage for the balls in the main body of the slider or carriage.
In the related art section of U.S. Pat. No. 6,902,322 B2 it is explained how dust may be prevented from entering a ball circulation passage by disposing seals for sealing the side walls of the guide rail and the inner walls of the movable element. Further, U.S. Pat. No. 6,902,322 B2 details improvements to such seals in order to improve flexion of the seals and reduce the risk of poor sealing conditions. This patent highlights the importance of using sealing structures to protect the ball bearing arrangements in linear guides.
Many environments are, however, inherently relatively dirty and inevitably will expose a linear guide to a number of substances which might fill a ball bearing arrangement thereby clogging the ball circulation paths. This invariably leads to a requirement for cleaning at regular intervals or to a complete blockage and a non-functioning sliding function.
Ball-bearing arrangements provide superior sliding operation when clean and manufactured to tight tolerances, but on the other hand, they are expensive and complicated elements which are susceptible to clogging by dust and the other substances in its environment.